1. Field of the Invention
The present invention relates to a data outputting method, a data outputting device using the method and a liquid crystal panel driving device and a liquid crystal device using the method and a device, and more particularly to the data outputting method capable of reducing a memory capacity of a Look-Up Table (hereinafter simply, a LUT) and of a memory and/or, of shortening time of transferring data, the data outputting device using the method, the liquid crystal panel driving method, the liquid crystal panel driving device and the liquid crystal displaying method and the liquid crystal display device using the method and the device.
The present application claims priority of Japanese Patent Application No. 2004-335998 filed on Nov. 19, 2004, which is hereby incorporated by reference.
2. Description of the Related Art
As a displaying method in an image display device such as a liquid crystal device or a like, conventionally, a multiframe method is employed. In the multiframe method, a LUT is used for displaying in every frame.
An example of known use of the LUT is explained by referring to FIG. 6. For example, 10-bit addresses are supplied to a LUT 14 from an address supplying section 12 and then gray-scale data is read from the LUT 14 and the read gray-scale data is fed from the gray-level data outputting section 18 to a gray-level controlling input port (not shown) for being placed under a display control of a liquid crystal panel. DATA 11:0 in a data column in FIG. 6 shows that its number of bits is 12.
Moreover, another example related to the LUT is a method for reducing a memory capacity of the LUT. This reducing method is disclosed in Japanese Patent Application Laid-open No. 2001-143063 (Patent Reference 1) in which, by inputting an input value obtained by dropping low-order bits making up input data and a value being larger by one (or smaller by one) than the input data so that two output values corresponding to the above two values are output from the LUT and, by performing interpolation between the two output values based on data made up of the dropped low-order bits, an output value corresponding to an original value is gained.
In the above Patent Reference 1, technology to solve problems in that, when an output value calculated by performing interpolation between two output values is obtained by the above reducing method, the LUT must be read twice is also disclosed. An image processing device using the above technology includes an input compressing section to compress input data X0 representing each pixel value of an input image and to output the compressed data X1 and to output an interpolated data X2, a LUT to output data Yx corresponding to the compressed data X1 fed from the input compressing section and related data Dy, and an interpolating section to interpolate the data Yx output from the LUT based on the interpolated data X2 fed from the input compressing section and the related data Dy fed from the LUT to output a desired output data Y0 and is so configured as to perform interpolation of the output data Yx by using the interpolated data X2 and related data Dy. Here, the related data Dy is data showing a relation between the data Yx output from the LUT and data Yx′ corresponding to the compressed data X1′ existing before or after the compressed data X1.
Other technologies to interpolate data output from a LUT are disclosed in Japanese Patent Application Laid-open Nos. Hei 7-222197 (Patent Reference 2) and 2004-109796 (Patent Reference 3). In the technology disclosed in the Patent Reference 2, interpolated data is produced by using an interpolation coefficient output from a LUT and low-order bits making up color signal data in the first colorimetric system and, by adding the produced interpolated data to main data output from the LUT, color signal data in the second calorimetric system is interpolated.
In the technology disclosed in the Patent Reference 3, high-order bits making up input data (target gray-level) and high-order bits making up input data (target gray-level) in a previous frame are input as an address to the LUT to make interpolated date be output from the LUT so that, based on the low-order bits of the output interpolated data and input data and low-order bits making up input data in a previous frame, correcting data is produced.
However, the above examples of using the LUT present problems. That is, when the number of gray-level displays is to be increased, a memory capacity to satisfy the increased number is required, which causes a large memory capacity and high costs. Though the method to reduce the memory capacity of the LUT to solve this problem is disclosed in the above Patent References 1, 2 and 3, and technologies to interpolate data to be output from the LUT are also disclosed. However, the Patent References 1, 2, and 3 do not suggest fully how the problems are solved.
That is, in the Patent References 1, 2 and 3, the example of the case in which the interpolation of data necessary to solve the specified technological issues is performed under a condition being closely and inseparably related to the technological problems of each of the issues is shown and the technology to interpolate output data of the LUT is also disclosed therein, however, no satisfactory suggestion is provided as to how data is interpolated from a view point of how memory capacity is to be reduced and/or how transfer speed of data is to be increased successfully.